Question

Number of straight lines passing through $(1,3),(7,-3),(5,-1),(6,-2)$ is

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is A 1

$\frac{y-3}{x-1}=\frac{3+3}{1-7}=\frac{6}{-6}=-1$

$y-3=-x+1$

$x+y=4$

$x=7,y=-3$

$x=5,y=-1$

$x=6,y=-2$

$\therefore$ the given points are collinear.

$\therefore$ only one line passes through them.